Download Ashley John - Sickle Cell Anemia

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Sickle Cell
Anemia
Ashley John
IntroSem118Q
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Prof. Brutlag October 1, 2008
What is Sickle Cell?
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Autosomal recessive disease
Caused by E6V point mutation in hemoglobin beta gene
(HBB) found on chromosome 11p15.5
Most common inherited blood disorder in US (72, 000)
Homozygous Sickle Cell Disease (Hb SS) accounts for 6070% sickle cell disease cases in the United States
Common in people of African, Mediterranean, Middle
Eastern, and Indian ancestry
Also common in persons from the Caribbean and parts of
Central and South America
8% the African-American population are carriers
Sickle Cell Diagram
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In SCA a point mutation
causes Glu to be replaced
by Val in B chains of HbA
(HbS)
Low oxygen levels RBCs with
HbS become sickled
Sickled cells block small
vessels producing occlusions
which cause necrosis of the
tissue
Symptoms/Complications
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Pain associated with
vaso-occlusive crises
Chronic hemolytic anemia
Severe infections
Pulmonary hypertension
Priapism
Stroke
Delayed growth and
sexual maturation
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Abdominal pain
Poor appetite
Fatigue
Cough
Night sweats
Acute Chest Syndrome
Organ dysfunction
Leg ulcers
Problems Arising with Age
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Renal impairment
Lower hemoglobin
levels
Respiratory failure due
to Acute Chest
Syndrome
Classical Treatment
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No cure
Lifelong comprehensive care- routine health
maintenance and medications
Fluids
Painkillers
Antibiotics
Transfusions
Hydroxyurea (crises)- prevents sickling
Oxygen
Immunizations
Genetic Diagnosis
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Testing for the EV6 mutation of HBB
 Confirmatory
 DNA
testing
-based
 Carrier
testing
 High-performance
liquid chromatography(HPLC)
 IEF-based
 Prenatal
 By
diagnosis
analysis of DNA from fetal cells obtained by
amniocentesis usually performed at about 15-18 weeks'
gestation or chorionic villus sampling (CVS) at about 10-12
weeks' gestation.
Genetic Treatment
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All are under investigation
 Experimental
drugs
 Gene therapy
Additional Information
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Most healthy at birth; symptomatic later in infancy
or childhood after fetal hemoglobin (Hb F) levels
decrease and hemoglobin S (Hb S) levels increase
Life span normally 40-50 years, though have been
reported much longer
Avoid dehydration, temperature extremes, physical
exhaustion
Heterozygotes (Hb AS)- usually no symptoms
Sources
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OMIM
Clinical Trials
Gene Reviews
Genes and Diseases